Energy efficient solar powered high voltage direct current based data center

ABSTRACT

A system and method for providing power is disclosed. A variable direct current (DC) power source provides a variable DC voltage. A configurator dynamically converts the variable DC voltage to a selected DC voltage to provide the power. A set of switches combines the solar voltage with a substantially constant DC voltage. A control unit controls the set of switches and the configurator to provide the combined voltages at a selected voltage level.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. Non-Provisional applicationSer. No. 13/661,367, entitled “ENERGY EFFICIENT SOLAR POWERED HIGHVOLTAGE DIRECT CURRENT BASED DATA CENTER,” filed on Oct. 26, 2012, whichis incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates to power systems and, in particular, to asolar energy power system for providing DC power to an electrical load.

One of the biggest costs in operating a data computing centers is powercost. Power is needed to operate servers and storage systems. Sincethese servers and storage systems heat up, more power is then needed inorder to provide air conditioning and other cooling systems. Solar powerhas been proposed as an alternative or supplemental power source fordata computing centers. However, current methods of supplying solarpower use an inefficient method of converting direct current (DC)voltage from solar panels to an alternating current (AC) voltage that isthen supplied to a power grid coupled to the data computing center.

SUMMARY

According to one embodiment, a system for providing power includes: avariable direct current (DC) power source that provides a variable DCvoltage; and a configurator configured to dynamically convert thevariable DC voltage to a selected DC voltage to provide the power.

According to another embodiment, a method of powering an electronicdevice includes: receiving a variable DC voltage from a variable DCpower source; dynamically converting the variable DC voltage to aselected DC voltage; and providing the selected DC voltage to theelectronic device.

According to another embodiment, a system for supplying solar energy toa location includes: a configurator configured to convert variabledirect current (DC) voltage from one or more solar panels to selectedsolar voltage; a source of substantially constant DC voltage; and a setof switches configured to combine the solar voltage and thesubstantially constant DC voltage; and a control unit configured tocontrol the set of switches and the configurator to provide the combinedvoltages at a selected voltage level.

Additional features and advantages are realized through the techniquesof the present disclosure. Other embodiments and aspects of thedisclosure are described in detail herein and are considered a part ofthe claimed disclosure. For a better understanding of the disclosurewith the advantages and the features, refer to the description and tothe drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter which is regarded as the disclosure is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The forgoing and other features, and advantages ofthe disclosure are apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings in which:

FIG. 1 shows a diagram of an exemplary power system of the presentdisclosure;

FIG. 2 shows a detailed view of an exemplary solar array module of thepresent disclosure;

FIG. 3 shows an exemplary placement of measurement devices formonitoring an operation of the exemplary power system of the presentdisclosure;

FIG. 4 illustrates an exemplary operational mode of the exemplary powersystem using only AC-rectified DC voltage;

FIG. 5 illustrates an exemplary operational mode of the exemplary powersystem using a mixture of an AC-rectified DC voltage and a solarvoltage;

FIG. 6 shows another exemplary operational mode of the exemplary powersystem that uses only solar energy;

FIG. 7 shows a schematic representation of a solar panel configurationof the exemplary power system;

FIG. 8 shows an exemplary solar array configurator of the exemplarypower system of the present disclosure;

FIG. 9 shows a basic internal configuration of the exemplary solar arrayconfigurator of FIG. 8;

FIG. 10 shows an exemplary parallel switch configuration of theconfigurator of FIG. 8;

FIG. 11 shows an exemplary serial configuration of the configurator ofFIG. 8;

FIG. 12 shows another serial configuration of the configurator of FIG.8;

FIG. 13 shows an exemplary hybrid HVDC power supply module in oneembodiment of the present disclosure;

FIG. 14 shows an exemplary extension of the exemplary hybrid HVDC powersupply module of FIG. 13;

FIG. 15 shows a flowchart illustrating a method of initializing thepower supply system of the present disclosure;

FIG. 16 shows a flowchart illustrating a method of initializing a solarinput module of the exemplary power system of the present disclosure;

FIG. 17 shows a flowchart illustrating a method of operating a solarmodule of the exemplary power system of the present disclosure;

FIG. 18 shows an exemplary flowchart of a method for operating arectifier module of the exemplary power system of the presentdisclosure;

FIG. 19 shows an exemplary flowchart of a method for providingcontinuity of the exemplary power supply of the present disclosureduring a solar array reconfiguration; and

FIG. 20 shows a configurator combination that may be suitable forproviding voltages for large scale products

DETAILED DESCRIPTION

FIG. 1 shows a diagram of an exemplary power system 100 of the presentdisclosure. The exemplary power system 100 may receive input from avariable voltage source, such as an array of solar panels, as well asfrom a substantially non-variable voltage source, such as a rectifiedvoltage from a power grid, and may provide a suitable combination ofthese voltages to an electronic device. In various embodiments, theexemplary power system 100 provides power to a data center, computingcenter or other type of center that has high voltage direct current (DC)demands. The exemplary power system 100 includes to one or more stringsof solar panels, shown as String 1 (101 a), String 2 (101 b) and StringN (101 c) for illustrative purposes. An exemplary string of solar panelsmay include only one solar panel or may include multiple solar panelsthat are coupled to each other using a serial connection or a parallelconnection. The exemplary power system 100 further includes a rectifier103, such as the exemplary three-phase rectifier 103, which receivesinput from an alternating current (AC) power source, such as a powergrid (not shown), and outputs a rectified DC voltage. A solar arraymodule 105 receives the variable voltage from the one or more strings ofsolar arrays 101 a-101 n and the non-variable voltage from the rectifier103 and outputs a suitable combination of the received voltages. Thesolar array module includes a configurator (see FIG. 2) that isconfigured to provide a DC-DC voltage conversion from the variablevoltage provided by the string of solar panels to a selected voltage,referred to herein as the solar voltage. In one embodiment, theconfigurator dynamically places the strings of solar arrays into variouscombinations of serial and parallel connections, thereby changing avoltage output of the configurator. Operation of the solar arrayconfigurator is discussed further with respect to FIGS. 7-12. The solararray module also includes a series of switches that may be configuredto connect or disconnect the configurator and the rectifier 103 invarious combinations, as discussed below with respect to FIGS. 2 and 3.The switches either isolate the solar panels, isolates the rectifier orcombines them in various operational modes, as discussed below withrespect to FIGS. 4-6.

The exemplary power system further includes a regulator module 107. Theregulator module 107 may include a voltage regulator suitable forregulating the rectified voltage signal using at least one of a buckconverter for decreasing a voltage output or a boost converter forincreasing a voltage output, and a maximum power point tracking (MPPT)device that provides a suitable load to the solar voltage to obtain aselected power, usually a maximal power, from the solar voltage. A lowpass filter 109 receives the regulated voltage from the regulator module107 and is configured to remove residual high-frequency fluctuations inthe regulated voltage and to provide an output voltage as high-voltagedirect current (HVDC) voltage. The HVDC voltage may be supplied directlyto the exemplary data center or to an intervening device such as aninternal bus line or a battery, for example.

FIG. 2 shows a detailed view of an exemplary solar array module 105 ofthe present disclosure. The exemplary solar array module 105 includesone or more switches S1-S6 for selecting a coupling between a rectifier202 and a solar array configurator 204. The solar array configurator 204may be coupled to the exemplary string of solar panels 101 a-101 n (seeFIG. 1). The solar array module 105 outputs a voltage to load 208according to the selected operational mode of the solar array module105. In one embodiment, the solar array module 105 may be coupled to aninverter 206 that provides excess generator power within the solar arraymodule 105 to a power grid. In alternative embodiments, the solar arraymodule 105 may be coupled to a local power storage device. Variousmeasurement devices are coupled to the solar module to control anoperation of the exemplary power system 100, as discussed with respectto FIG. 3.

FIG. 3 shows an exemplary placement of measurement devices formonitoring an operation of the exemplary power system 100. Ammeter 301measures a current supplied by the rectifier 320, and voltmeter 303measures a solar voltage across the solar array configurator 204.Ammeter 305 and voltmeter 307 measure current and voltage, respectively,provided by the voltage regulator 310 to an exemplary load of thecircuit, i.e., the exemplary data center. In various embodiments, abattery bank 312 may be coupled to the line voltage of the voltageregulator via a charge controller 314. The battery bank power may beused during switching times between the exemplary operational modesdisclosed herein, wherein the batteries provides a constant voltage tothe output of the voltage regulator 310 that fills in for an absence ofvoltage during the flipping of the switches when changing operationalmodes. Typical switching times are on the order of a few milliseconds.

FIG. 4 illustrates an exemplary operational mode 400 of the exemplarypower system 100 using only AC-rectified DC voltage. In variousembodiments, the operational mode 400 may be used when a voltagesupplied by the string of solar panels is zero or substantially zero(V_(solar)=0), such as at night or during extreme cloud cover. Therectifier 103 receives AC voltage 410 and supplies an AC-rectified DCvoltage 401 as output. The AC-rectified DC voltage 401 may includevarious voltage ripples as an artifact of the rectification. TheAC-rectified DC voltage 401 is received at the solar array module 105.In the exemplary operation mode 400 of FIG. 4, the switches of the solararray module 105 are configured to isolate the string of solar panels,so that no voltage is received from the solar panels at the solar arraymodule 105. The rectified voltage 301 is therefore passed from therectifier 103 through the solar array module 105 to the voltageregulator that may regulate the rectified voltage 401 via buck or boostconverter. The regulated voltage is then filtered at the filter 109 toprovide a selected HVDC voltage 407.

FIG. 5 illustrates an exemplary operational mode 500 of the exemplarypower system 100 using a mixture of AC-rectified DC voltage 401 and asolar voltage 501 from the string of solar panels. In variousembodiments, the mixed operational mode 500 may be used when a voltagesupplied by the string of solar panels is substantially non-zero(V_(solar)>0) but the current provided by the solar panels is less thanthe current load requirements of the load (I_(solar)<I_(load)). In theexemplary mixed operation mode 500, the solar array module 105 isconfigured to combine the voltage 401 from the rectifier 103 and thesolar voltage 501 obtained from the configurator. The configurator ofthe solar array module 105 is used to produce a DC-DC voltage conversionfrom the variable voltages of the strings of solar panels to theselected solar voltage, V_(solar). The combined rectified voltage 401and solar voltage 501 are output to the regulator 107. The regulator 107provides either a buck conversion or a boost conversion to at least oneof the rectified DC voltage 401 and the solar voltage 501, to meet aselected downline voltage condition. The combined voltages are thenfiltered at filter 109 to provide a selected HVDC voltage 507.

FIG. 6 shows another exemplary operational mode 600 of the exemplarypower system that uses only solar energy. In various embodiments, thispurely-solar operational mode 600 may be used when a power provided bythe string of solar panels is substantially equal to a power requirementof the load, such as the exemplary data center. (P_(solar)=P_(load)). Inthe exemplary operation mode 600, the rectifier 103 is isolated from thesolar array module 105, and the solar array module 105 thereforereceives only the variable voltages from the string of solar panels. Theconfigurator combines the variable voltages using exemplary methodsdisclosed herein to provide a selected solar voltage V_(solar) 601 tothe voltage regulator 107. The voltage regulator 107 bucks or boosts thesolar voltage to a selected output voltage 605 according to exemplarymethods disclosed herein. Filter 109 then filters the voltage to providea selected HVDC voltage 607.

Another operational mode (not illustrated) may be used to store excesspower from the string of solar panels. This operational mode may be usedwhen power provided by the string of solar panels is greater than thepower requirements of the load, (P_(solar)>P_(load)) Excess generatedpower may be stored in an energy storage device, such as a chargeablebattery, for example, or supplied to the power grid.

Returning to FIG. 2, switches S1-S6 may be configured to select a modeof operation of the exemplary power system 100 from among the exemplaryoperational modes discussed above. To operate in the exemplaryoperational mode 200 (no solar energy), switches S1 and S4 are closedwhile the remaining switches S2, S3, S5 and S6 are left open. To operatein the exemplary operation mode 300 (mixture of solar energy and gridenergy), switches S1, S2 and S3 are closed, while switches S4, S5 and S6are left open. To operate in the exemplary operational mode 400 (solarenergy only), switches S2, S3 and S5 are closed while switches S1, S4and S6 are open. The discussed operational mode in which excess solarpower is stored may be obtained by closing switches S2, S3, S5 and S6,while leaving switches S1 and S4 open. Measurement and switching controlunit 210 may be used to monitor various parameters of the exemplarypower system 100 and the solar array module 500 to select a suitablemode of operation. The switches may be solid state switches and/ortraditional relay switches.

FIGS. 7-12 illustrate methods of using the solar array configurator toprovide solar energy to the exemplary data center. FIG. 7 shows aschematic representation of a solar panel configuration of the exemplarypower system 100. Each of the solar panels 700 a, 700 b, . . . , 700i-1, 700 i, . . . , 700 n may be strung together in various combinationsof parallel connections and serial connections according to loadrequirements. Stringing the panels together in a parallel connectionincreases the total current output and the string's current carryingcapacity. Stringing the panels together in a serial connection increasesthe total voltage output. In an exemplary embodiment, the number ofparallel connections is selected so as to be greater than a ratio of thecurrent requirements of the load to a maximal current carrying capacityof a string, as shown in Eq. (1).N _(p) ≧I _(load) /I _(panel(max))  Eq. (1)

Additionally, the number of serial connection is generally selected soas to be greater than a ratio of the minimum load voltage to a voltageof a solar panel, as shown in Eq. (2).N _(s) ≧V _(load(min)) /V _(panel)  Eq. (2)

FIG. 8 shows an exemplary solar array configurator 800 of the exemplarypower system 100. The solar array configurator 800 receives voltagesfrom a plurality of strings of solar panels (String 1, . . . , String 8)as input and performs a DC-DC voltage conversion to provide an outputvoltage (V_(solar)). One goal of the solar array configurator 800 is toprovide a solar voltage such that a total voltage output of the solarvoltage and the rectified voltage is greater than a load voltagerequirement. Then, the total voltage output may be bucked to obtain aselected voltage level. In general, buck voltage conversion is moreefficient than boost voltage conversion. The configurator thereforeensures that solar strings 1-8 are dynamically reconfigured in one or aseries connection and a parallel connection in order to sustain high DCvoltage levels. The solar voltage output from the configurator 800,referred to herein as HVDC_(SOL), is constrained by Eq. (3):Σ_(i=1) ^(n) Vmin_(STR-i)≦HVDC_(solar) ≦Vmax_(STR-n)  Eq. (3)

Although eight strings of solar panels (representative of the solarpanels 700 a-700 n of FIG. 7) are shown for illustrative purposes, anyselected number of strings of solar panels may be provided to the solararray configurator 800 in alternate embodiments. The solar arrayconfigurator 800 further includes a measurement and control unit 802that selects switch configurations to perform the DC-DC conversion usingthe methods discussed below with respect to FIGS. 9-12.

FIG. 9 shows a basic internal configuration of the exemplary solar arrayconfigurator 800. FIG. 9 shows four strings 901 a-901 d of solar panelsprovided at an input side of the solar array configurator 800. Eachstring includes two lines, generally a high voltage line and a lowvoltage line, labeled H and L, respectively. Measurement devices 903a-903 d are provided for string inputs 901 a-901 d, respectively. Aselected measurement device measures a voltage between the high line andthe low line of the corresponding string. The measured voltage isgenerally variable, since it is a result of solar energy and istherefore affected by various random environmental conditions. Ameasured voltage may be transmitted to the measurement and control unit802 for operation of the solar array configurator 800. The high and lowlines of the strings are selectively coupled to one of the switches 905a-905 f. In the configuration of FIG. 9, the low line of string 1 (901a) is coupled to the input of switch 905 a, the high line of string 2(901 b) is coupled to the input of switch 904 b, the low line of string2 (901 b) is coupled to the input of switch 904 c, the high line ofstring 3 (901 c) is coupled to the input of switch 904 d, the low lineof string 3 (901 c) is coupled to the input of switch 904 e and the highline of string 4 (901 d) is coupled to the input of switch 904 f. Thehigh voltage line of string 1 (901 a) is not coupled to a switch inputbut is instead coupled to output of the switches 905 b, 905 d and 905 fto provide a composite high voltage line at the output of theconfigurator 800. Also, the low voltage line of string 4 (901 d) is notcoupled to a switch but is instead coupled to output of the switches 905a, 905 c and 905 e to provide a composite low voltage line at the outputof the configurator 800. The solar voltage (V_(solar)) output by theconfigurator is therefore a difference between the voltages of thecomposite high voltage line and the composite low voltage line. Each ofswitches 905 a-905 f may be placed in one of a parallel switch positionand a serial switch position and are coupled to each other so that thestrings may be dynamically connected in various combinations of parallelconnections and serial connections, as discussed below with respect toFIGS. 10-12. The measurement and control unit 802 may configure aselected switch to a selected position based on the measured voltagesobtained from the volt meters 903 a-903 d. In one embodiment, themeasurement and control unit may determine a configuration of switches905 a-905 d that provides a selected V_(solar) output and provide acommand to the switches 905 a-905 d to flip into a position suitable toprovide the determined configuration. Depending on the voltage level foreach string, the measurement and control 802 unit may serialize (connectin serial) or parallelize (connect in parallel) any set of stringstogether, and not only adjacent strings.

FIG. 10 shows an exemplary switch configuration of the configurator 900in which the strings 901 a-901 d are connected in parallel. The switches905 a-905 d are all flipped to a position that couples the high voltagelines of the strings 901 a-901 d with each other and coupled the lowvoltage lines of the strings 901 a-901 d with each other.

FIG. 11 shows an exemplary serial configuration of the configurator1000. Switches 905 a and 905 b are placed in a position so that the lowvoltage line of string 1 (901 a) is coupled to the high voltage line ofstring 2 (901 b), thereby serially connecting string 1 (901 a) andstring 2 (901 b). Also, switches 905 e and 905 f are placed in aposition so that the low voltage line of string 3 (901 c) is coupled tothe high voltage line of string 4 (901 d) thereby serially connectingstring 3 (901 c) and string 4 (901 d). Switches 905 c and 905 d remainin a parallel switch position. Thus, the high voltage line of V_(solar)is coupled to the high voltage lines of string 1 (901 a) and string 3(901 c), and the low voltage line of V_(solar) is coupled to the lowvoltage lines of string 2 (901 b) and string 4 (901 d). The serialconnections in FIG. 11 increase the voltage output of the configuratorfrom the same output from the configuration of FIG. 10. Switching fromthe configuration of FIG. 10 to the configuration of FIG. 11 may bereferred to a stepping to a next serialization level. Similarly,switching from the configuration of FIG. 11 to the configuration of FIG.10 may be referred to a stepping to a next parallelization level.

FIG. 12 shows another serial configuration of the configurator 800.Switches 905 a and 905 b are placed in a serial position so that the lowvoltage line of string 1 (901 a) is coupled to the high voltage line ofstring 2 (901 b). Switches 905 c and 905 d are placed in a serialposition so that the low voltage line of string 2 (901 b) is coupled tothe high voltage line of string 3 (901 c). Switches 905 e and 905 f areplaced in a serial position so that the low voltage line of string 3(901 c) is coupled to the high voltage line of string 4 (901 d).Therefore, the strings 1 through 4 (901 a-901 d) are entirely seriallyconnected. The high voltage line of V_(solar) is coupled to the highvoltage lines of string 1, and the low voltage line of V_(solar) iscoupled to the low voltage line of string 4. Switching from theconfiguration of FIG. 11 to the configuration of FIG. 12 may be referredto a stepping to a next serialization level. Similarly, switching fromthe configuration of FIG. 12 to the configuration of FIG. 11 may bereferred to a stepping to a next parallelization level.

FIG. 13 shows an exemplary hybrid HVDC power supply module 1300 in oneembodiment of the present disclosure. The exemplary hybrid HVDC powersupply module 1300 includes a solar input module 1301 and an AC inputmodule 1303. The solar input module 1301 includes a solar array inputconfigurator 1305 and a buck/boost conversion and maximum power pointtracking module 1307. The solar array input configurator 1301 receivessolar voltages V_(STR-1), . . . V_(STR-n) from a plurality of strings ofsolar panels (String 1, . . . String N) and provides an output voltageHVDC_(SOL) using the methods disclosed with respect to FIG. 7-12. Thebuck/boost conversion and maximum power point tracking module 1307performs either a buck conversion to lower HVDC_(SOL) or a boostconversion to increase HVDC_(SOL). The converted voltage is supplied toan internal HVDC bus 1320. The AC input module 1303 includes a rectifier1309 and a buck/boost converter 1311. In one embodiment, the rectifier1309 receives AC voltage from a power grid. In various embodiments, therectifier may also or alternately receive an AC voltage from anuninterrupted power supply. The rectifier 1309 converts the AC voltageto a substantially constant DC voltage, HVDC_(GRID). The buck/boostconverter 1311 may perform either a buck conversion to lower HVDC_(GRID)or a boost conversion to increase HVDC_(GRID). The converted voltage issupplied to the internal HVDC bus 1320. Thus, the voltage along theinternal HVDC bus (i.e., HVDC_(INT)) may be either solar voltage, gridvoltage or a combination of solar voltage and grid voltage. In variousembodiments, the internal bus voltage (i.e., vModuleOut) is maintainedbetween a low voltage (i.e., vBusLow) and a high voltage (i.e.,vBusHigh). In an exemplary embodiment, the internal bus voltage may bemaintained between about 380 volts and about 420 volts. The HVDC_(INT)is supplied to a power conditioner 1322 that supplies a voltage to theload, i.e., the data computing center.

FIG. 14 shows an exemplary extension of the exemplary hybrid HVDC powersupply module 1300 of FIG. 13. The internal bus 1320 extends from thepower supply module 1300 and may be further coupled to an optional ACinput module that provides wind-generated voltage and an AC input backupgenerator 1404. Additionally, internal bus line 1320 may be coupled to abattery charge controller 1406 for power storage.

Operation of the exemplary power system 100 includes various operationalstages. One stage may include initializing the power supply. Anotherstage may include initialization of the solar input module. Yet anotherstage may include operation of the solar input module according to aselected mode of operation. Yet another stage may include operating anAC rectifier module. Yet another stage may provide continuity of thepower supply system during reconfiguration of the solar arrays. Thesestages are discussed in detail with respect to the exemplary flowchartsof FIGS. 15-19.

FIG. 15 shows a flowchart 1500 illustrating a method of initializing thepower supply system 100. In box 1501, the rectifier module is turned onand raised to a fully operational state. Meanwhile, the solar module ismaintained in an OFF state. In box 1503, the rectifier output voltage isset to vBusLow.

FIG. 16 shows a flowchart 1600 illustrating a method of initializing thesolar input module. In box 1601, an average string voltage isdetermined. In box 1603, the configurator is configured to provide avoltage output (vModuleOut) that is greater than vBusLow. In box 1603,the MPPT module 1307 is started. In box 1607, buck/boost conversion isstarted to provide output at vBusLow. In box 1609, a high impedanceoutput state is disabled.

FIG. 17 shows a flowchart 1700 illustrating a method of operating thesolar module according to present disclosure. In box 1701, the voltageHVDC_(SOL) is monitored. In various embodiments, the voltage may bemonitored on a continuous basis, in various embodiments. In boxes 1703,1705 and 1707, a determination is made of the value of the vModulevoltage with respect to vBusHigh and vBusLow. If vModule is greater thanor equal to vBusHigh (box 1703), the method proceeds to box 1709 whereinthe HVDC_(SOL) is buck converted so that vModule=vBusHigh. MaintainingvModule at vBusHigh is a desirable operating state of the power system.From box 1709, the method proceeds to box 1711 wherein a duty cycle ofthe converter is determined. Otherwise, vModule is compared to vBusHighand vBusLow in box 1705. If vModule is between vBusHigh and vBusLow, themethod proceeds directly to box 1711, where the duty cycle of theconverter is determined. If vModule is not between vBusHigh and vBusLow,the method proceeds to box 1707. In box 1707 if vModule is less thanvBusLow, then the method proceeds to box 1713 wherein HVDC_(SOL) isboosted so that vModule=vBusLow.

Looking now at box 1711, if the duty cycle of the buck converter issignificantly lower than 50%, then the configuration of the solarstrings is checked to see if the solar strings need to be parallelizedto a new level, as shown in boxes 1715, 1717, 1719 and 1721. If the dutycycle is not significantly lower than 50%, the method proceeds from box1711 to box 1701 to monitor solar string voltages.

Returning now to boxes 1715, 1717, 1719 and 1721, in box 1715 adetermination is made whether the solar strings need to be parallelizedto the next level. If the answer is NO, then the method proceeds to box1716. In box 1716, excess energy is exported back to the grid and theprocess then returns to box 1701 to monitor the solar string voltages.If the answer to the parallelization question in box 1715 is YES, thenthe method proceeds to box 1717. In box 1717, the power source isadjusted so that the power is obtained from the rectified AC voltagesource. Then in box 1719, the wires of the solar strings arereconfigured (to the next parallelization level). In box 1721, the solarpower source is restored as the primary power source. After box 1721,the method proceeds to box 1701 to monitor solar string voltages.

Looking now at box 1713, once the HVDC_(SOL) is boosted so thatvModule=vBusLow, the method proceeds to check to see if the solarstrings need to be serialized to a new level. In box 1723 adetermination is made whether the solar strings need to be serialized tothe next level. If the answer is NO, then the method proceeds to box1724. In box 1724, a determination is made if the energy consumption fora boost is more than energy supplied to by the solar voltage. If theanswer in box 1724 is NO there is not enough solar voltage supplied, themethod proceeds to box 1701 to monitor solar string voltages. If theanswer in box 1724 is YES and there is enough solar voltage, the methodproceeds to box 1731. Returning to box 1723, if the answer is YES, thenthe method proceeds to box 1725. In box 1725, the power source isadjusted so that the power is obtained from the rectified AC voltagesource. Then in box 1727, the wires of the solar strings arereconfigured (to the next serialization level). In box 1729, the solarpower source is restored as the primary power source. After box 1729,the method proceeds to box 1701 to monitor solar string voltages.

In box 1731, the MPPT of the solar module is determined. If theconfigurator is at maximal serialization and the MPPT is still unviable,the solar module is shut off. In box 1733, the average string voltage ismonitored periodically in order to determine a suitable time to restartthe solar module. When a suitable time is determined, the solar moduleis awakened and the solar string voltages are monitored by returning tobox 1701.

FIG. 18 shows an exemplary flowchart 1800 of a method for operating therectifier module. In box 1801, the rectified voltage continuouslyfollows the solar module output voltage and maintains a same outputvoltage at the rectified module. In box 1803, output impedances of themodules (i.e., the solar module and the rectifier module) are equalized.In box 1805, the sum of the impedances of the modules is matched to aneffective impedance of the load at the internal DC bus.

FIG. 19 shows an exemplary flowchart 1900 of a method for providingcontinuity of power supply during a solar array reconfiguration. In box1901, the rectified DC voltage is moved above the solar module outputvoltage. In box 1903, the solar module voltage output is dropped belowvBusLow. In box 1905, a high impedance output state is enabled at thebuck/boost converter. In box 1907, strings of solar panels aredisconnected at the configurator. In box 1909, the strings are rewiredaccording to a selected configuration. In box 1911, the high impedanceoutput state of the buck/boost converter is disabled.

FIG. 20 shows a configurator combination that may be suitable forproviding voltages for large scale products. Solar configurator SAC1(2003) and solar configurator SAC2 (2005) are fed as inputs into a solarconfigurator aggregator SAC Agg (2001). The SAC Agg 2001 may be operatedas the exemplary configurator disclosed herein only having the output ofother solar configurators as input to the SAC Agg 2001. Thus, the SACAgg 2001 may be used to augment the serialization and parallelizationpower of the individual solar configurators SACT 2003 and SAC2 2005.Additional solar configurators may also be provided to SAC Agg 2001, asrepresented by input line SACN-IN.

The solar array configurator (call it, say, SAC) output can be fed as asingle string pair into yet another solar array configurator to addresslarge scale projects.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of onemore other features, integers, steps, operations, element components,and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present disclosure has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the disclosure in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the disclosure. Theembodiment was chosen and described in order to best explain theprinciples of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated

While the preferred embodiment to the disclosure had been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the disclosure first described.

What is claimed is:
 1. A method of powering an electronic device,comprising: receiving a high voltage line and a low voltage line fromeach of a plurality of variable DC power sources at a configurator;forming a combination of the high voltage lines to obtain a compositehigh voltage line at an output of the configurator; forming acombination of the low voltage lines to obtain a composite low voltageline at an output of the configurator, wherein a solar voltage is adifference between the composite high voltage line and the composite lowvoltage line; receiving a substantially constant DC voltage from aconstant DC power source; combining the solar voltage with thesubstantially constant DC voltage to obtain the selected DC voltage; andproviding the selected DC voltage to the electronic device.
 2. Themethod of claim 1, wherein the variable DC power source includes atleast one of a solar panel; and a wind-powered generator.
 3. The methodof claim 1, further comprising receiving the substantially constant DCvoltage from at least one of a rectifier and a battery.
 4. The method ofclaim 1, further comprising configuring a set of switches to perform oneof: isolating the variable DC power source; isolating constant DCvoltage source; and combining the solar voltage with the substantiallyconstant DC voltage.
 5. The method of claim 1, wherein the configuratorforms the combination of the high voltage lines using one or more ofparallel and series connections and forms the combination of the lowvoltage lines using one or more of parallel and series connections. 6.The method of claim 5, further comprising selecting the parallel andseries connections based on voltage measurements taken from the highvoltage lines and the low voltage lines at the configurator.
 7. Themethod of claim 1, further comprising performing one of a buckconversion and a boost conversion to convert the combination of thesolar voltage and the substantially constant DC voltage to obtain theselected DC voltage.
 8. The method of claim 1, further comprisingconfiguring the variable DC voltage so that the obtained selected DCvoltage meets a load requirement of the electronic device.